When pumpkins are grown in elevated temperatures (32/27 °C day/night) for 1 week during flower development, fewer female flower buds are formed than at normal temperatures (20/15 °C) and only a small percentage of these reach anthesis. To determine if application of the ethylene-releasing compound ethephon can overcome the suppression of female flowers at high temperatures, `Baby Bear' pumpkin plants were sprayed at the two-leaf stage with 100 or 300 μL L–1 ethephon and then grown in hot and cool greenhouse compartments. At 20/15 °C, 17% of the first 15 main stem nodes produced female flower buds on control plants and virtually all of these developed into open flowers. The higher rate of ethephon increased female bud percentage to 37%. At 32/27 °C, only 3% of the nodes formed female flower buds and 2% flowered. Application of ethephon did not significantly increase female expression at high temperature, and none of the buds reached anthesis. Treatment with the inhibitor of ethylene action silver thiosulfate reduced female flower bud formation at the low temperature and entirely suppressed female flower buds at high temperature. In two additional experiments, these treatments were applied to two cultivars grown at a less extreme 32/20 and at 20/15 °C. Female buds and open flowers were moderately increased by ethephon in the high temperatures, suggesting that ethephon might foster female flowering in less extreme temperatures. Further work is needed to determine if ethephon treatment can overcome the heat-induced inhibition of female flowers in pumpkin under field conditions.
R. Bruce Carle and J. Brent Loy
Genetic experiments were initiated to assess the potential for combining large seed size from PI 285611, a large-fruited, hullless seeded accession, with small fruit size from a hullless seeded breeding line (NH29-13-5-4). An F2 population and parental line were field-grown during Summer 1993 to determine inheritance and heritability of large seed size and the relation between fruit and seed size. Seed size variables of weight, width, length, and thickness were regressed against fruit weight. There was a moderate, positive correlation between large fruit and seed length (R2 = 0.46). However, seed thickness, a major determinant of seed weight, was not correlated with fruit size. In an F2 population of ≈450 plants, there was a small number of plant selections with fruit under 1.5 kg and seed size approaching that of PI 285611.
Christian A. Wyenandt, Joseph R. Heckman and Nancy L. Maxwell
spp.) of pumpkin ( Cucurbita pepo ) and its control with cover crop mulches The Ohio State Univ Columbus PhD Diss.
Amanda Skidmore, Neil Wilson, Mark Williams and Ric Bessin
Muskmelon ( Cucumis melo ), squash ( Cucurbita sp.), cucumber ( Cucumis sativa ), pumpkin ( Cucurbita pepo ), and other cucurbit crops are valued at more than $1.6 billion per year in the United States ( U.S. Department of Agriculture, 2017
Katie J. Kammler, S. Alan Walters and Bryan G. Young
-o-lantern pumpkins ( Egel et al., 2005 ), although stunting and chlorosis injury is often observed on pumpkin plants. Halosulfuron has also been shown to injure squash ( Cucurbita pepo L.), especially when applied POST. Although squash plants begin to recover from
Megan E. O’Rourke and Jessica Petersen
herbicide and cover crop on weed control in no-till jack-o-lantern pumpkins ( Cucurbita pepo L.) production Crop Prot. 29 30 33 Walsh, J. Wuebbles, D. Hayhoe, K. Kossin, J. Kunkel, K. Stephens, G. Thorne, P. Vose, R. Wehner, M. Willis, J. Anderson, D. Doney
Organization, Rome, Italy Al-Omran, A.M. Sjeta, A.S. Falatah, A.M. Al-Harbi, A.R. 2005 Effect of drip irrigation on squash ( Cucurbita pepo ) yield and water-use efficiency in sandy calcareous soils amended with clay deposits Agr. Water Mgt. 73 43 55 Ayars, J
S. Alan Walters
The use of NT practices for pumpkin ( Cucurbita pepo ) production is becoming popular in the eastern and midwestern United States ( Harrelson et al., 2007 ; Morse et al., 2001 ; O’Rourke and Peterson, 2016 ; Rapp et al., 2004 ; Walters, 2016
Charles Zachry Ogles, Joseph M. Kemble, Amy N. Wright and Elizabeth A. Guertal
. Thus, the objective of the research was to evaluate the use of HFF as a source of organic N along with inorganic N sources at various rates in a plasticulture rotation of yellow squash ( Cucurbita pepo cv. Conqueror III) (Seminis Seed Co., St. Louis
E. Ryan Harrelson, Greg D. Hoyt, John L. Havlin and David W. Monks
Throughout the southeastern United States, vegetable growers have successfully cultivated pumpkins (Cucurbita pepo) using conventional tillage. No-till pumpkin production has not been pursued by many growers as a result of the lack of herbicides, no-till planting equipment, and knowledge in conservation tillage methods. All of these conservation production aids are now present for successful no-till vegetable production. The primary reasons to use no-till technologies for pumpkins include reduced erosion, improved soil moisture conservation, long-term improvement in soil chemical and microbial properties, and better fruit appearance while maintaining similar yields compared with conventionally produced pumpkins. Cover crop utilization varies in no-till production, whereas residue from different cover crops can affect yields. The objective of these experiments was to evaluate the influence of surface residue type on no-till pumpkin yield and fruit quality. Results from these experiments showed all cover crop residues produced acceptable no-till pumpkin yields and fruit size. Field location, weather conditions, soil type, and other factors probably affected pumpkin yields more than surface residue. Vegetable growers should expect to successfully grow no-till pumpkins using any of the winter cover crop residues tested over a wide range in residue biomass rates.